The present invention generally relates to an integrated motor and control system, and more particularly to an integrated electric motor and control system protected by a housing having an opening through which a heat sink extends.
Electric motors are commonly used in appliances, such as clothes washing machines, clothes dryers, and the like. It is common for a motor control to be mounted on the motor to control various aspects of motor operation, such as motor speed. The electric motor control is commonly at least partially enclosed in a housing to protect the motor and control. For example, in some appliances it is possible for the motor or its control to encounter liquid (e.g., water from condensate or wet clothes). The housing can prevent the liquid from contacting the motor control, protecting electronic components of the control from liquid. An electric motor and control can be provided to an appliance assembly line as an integrated unit to facilitate assembly of the appliance. For example, the motor control can be connected to and mounted on the motor by a motor manufacturer who may also attach a protective housing to protect the motor control.
Although it is desirable to protect the motor control from exposure to water or other liquids, it is also desirable to cool the motor control to prevent its heat-sensitive components from overheating. Cooling is commonly accomplished by mounting a heat sink in thermal communication with the control. As is generally known, a heat sink commonly has a body including a relatively large thermal mass to absorb heat. Some heat sinks have cooling fins extending from the body to facilitate heat transfer from the heat sink away from the control and/or motor. The cooling fins can more effectively transfer heat away from the control when the fins are outside the housing protecting the motor control where cooler air is available to pass over the fins. An opening can be provided in the housing to allow the fins to extend outside the housing. Although such an opening is desirable for cooling, the opening can permit liquid to get into the housing and contact the control. In appliances in which it is foreseeable that water or other liquids may be present, a drip shield can be positioned to extend over the top of the opening and the cooling fins to divert the liquid away from the opening. However, the drip shield can also undesirably interfere with cooling air flow over the fins.